Angular Interrogation Research Articles

Detection of Serratia marcescens and Mierococcus lysodeikticus Bacterial Cells Using Cerium Oxide/Transition Metal Dichalcogenides Heterostructure‐Based Surface Plasmon Resonance Sensor

This article explores a novel surface plasmon resonance sensor for detecting the Serratia marcescens and Mierococcus lysodeikticus bacteria cells employing the cerium oxide (CeO2) and transition metal dichalcogenides heterostructure. The proposed sensor is designed based on the Kretschmann configuration, where silver (Ag) is deposited over a prism's surface to excite the surface plasmons. The transfer matrix method and angular interrogation technique are exploited for analyzing the sensor's performance at a wavelength of 633 nm. Firstly, the optimization of the prism and metal film is analyzed by selecting the minimum reflectance, better sensitivity, and quality factor. Secondly, the influence of the proposed structure in the sensor is executed by the performances of different structures, which are made with defined layers. Thirdly, different sensing parameters are analyzed for the considered bacterial cells, resulting in the maximum attained parameters being a sensitivity of 369.40° RIU−1, QF of 151.35 RIU−1, and detection accuracy of 7.57. Finally, the comparative study also shows the noteworthy enhancement using the proposed sensor compared with existing work. Therefore, the proposed sensor can be used as a carrier for detecting the bacterial cells and establishing a new platform for biomolecular and biomedical applications.

Nanosensors Based on Bimetallic Plasmonic Layer and Black Phosphorus: Application to Urine Glucose Detection.

This paper presents a new biosensor design based on the Kretschmann configuration, for the detection of analytes at different refractive indices. Our studied design consists of a TiO2/SiO2 bi-layer sandwiched between a BK7 prism and a bimetallic layer of Ag/Au plasmonic materials, covered by a layer of black phosphorus placed below the analyte-containing detection medium. The different layers of our structure and analyte detection were optimized using the angular interrogation method. High performance was achieved, with a sensitivity of 240 deg/RIU and a quality factor of 34.7 RIU-1. This biosensor can detect analytes with a wide refractive index range between 1.330 and 1.347, such as glucose detection in urine samples using a refractive index variation of 10-3. This capability offers a wide range of applications for biomedical and biochemical detection and selectivity.

Plasmonic wave assessment via optomechatronics system for biosensor application

Transduction biosensor (mass-based, optical and electrochemical) involves analysis, recognition and amplification in the acquired sample. In this work, the plasmonic-based biosensor was employed without using tags. It is crucial to determine angles of Brewster (Ɵb) and critical (Ɵc) for generating plasmonic resonance (Ɵr). The objective is to verify a cost-effective plasmonic biosensor through Fresnel simulation and experimentation of a developed optomechatronics system. The borosilicate glass, Au and Air layers were simulated with the Winspall 3.02 simulator. The optomechatronics system consists of: 1-optics (650 nm laser, slit, polarizer, photodiode), 2-mechanical (bipolar stepper motors, gears, stages) and 3-electronics (PIC18F4550, liquid crystal display (LCD) and drivers). Later, the software performs angular interrogation by reading the reflected beam from a rotating prism at 0.1125. Experimentation to simulation accuracy indicates that percentage differences for Ɵr and Ɵc are 1% and 0.2%, respectively. In conclusion, excellence verification was successfully achieved between experimentation and simulation. It proved that the low-cost optomechatronics system is capable and reliable to be deployed for the biosensor application.

High performance SPR sensor using 2-D materials: A treatise on design aspects, material choice and figure of merit

2D material-based surface plasmon resonance (SPR) sensors have piqued attention of the researchers due to their enhanced sensitivity. The performance characteristics of a 2D material-based SPR sensor in angular and spectral interrogation were extensively studied using simulations in this work. The performance parameters were studied with various existing configurations and a new design using Cu with 2D materials was proposed for enhanced performance. A treatise of various design aspects, material choices was performed to conclude on a sensor design with the highest figure of merit (FOM). Substituting the silver metal layer with a copper metal layer increased the FOM by around 3.3–3.6 times. Field profiles were also evaluated, resulting in a 1.15–1.17-fold improvement over the standard designs. The present study provides a detailed overview on the 2D material integrated SPR sensors and can be useful for development of high performance biosensors.

Coherent Control of Angular Interrogation of Sensitivity of the Surface Plasmon Polariton Waves at the Interface of Metal and Dielectric Medium

Coherent Control of Angular Interrogation of Sensitivity of the Surface Plasmon Polariton Waves at the Interface of Metal and Dielectric Medium

Highly sensitive Ag/BaTiO3/MoS2 nano composite layer based SPR sensor for detection of blood and cervical cancer

In this article, a nano-composite Ag/BaTiO3/MoS2 multilayer coating-based surface plasmon resonance (SPR) sensor with high sensitivity and figure of merit for the detection of cancer cells is analyzed. The proposed SPR biomedical sensor structure is built on the angular interrogation approach to utilizing the refractive index component, attenuated total reflection (ATR) analysis is employed to identify different kinds of cancer cells. The resonance angle varied as the refractive index (RI) of healthy and cancerous cells changed. Which ranged from 1.368 to 1.392 for increasing concentration in cervical (HeLa cells) and blood (Jurkat cells), RI 1.376 to 1.390 changes as the concentration of cancerous cells increases in healthy cells. The maximum estimated sensitivities for cervical (HeLa) and blood (Jurkat) cancer cells based on numerical data were 271.25 deg/RIU and 290.714 deg/RIU, respectively. The proposed BK7/Ag/BaTiO3/ MoS2has the ability to identify cancerous and healthy cells with the greatest overall sensitivity, as demonstrated by layered structures. Finally, the numerical results analyzed in this manuscript revealed a high degree of sensitivity and FoM compared to those of previous research studies.

Angular surface plasmon resonance-based sensor with a silver nanocomposite layer for effective water pollution detection

For sensing various samples of polluted water and various sodium chloride concentrations using an angular surface plasmon resonance (ASPR), we have introduced a conventional structure and a hybrid heterostructure in the current research. The suggested structures are composed of silver metal, dielectric layers, silver nanocomposite, and a sensing medium. The reflectance spectra of all structures in the visible region were obtained through the utilization of the transfer matrix method by using the angular interrogation method depending on the Kretschmann configuration. Through our findings, five substrate parameters have been optimized to attain the utmost level of sensitivity across all structures: the thickness of Ag-metal, the type and thickness of dielectric materials, the host material type and the volume fraction of nanoparticles for the nanocomposite layer. In this regard, the suggested sensor provides excellent performance with a sensitivity of 448.1°/RIU\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$/\ ext{RIU}$$\\end{document}, signal-to-noise ratio of 0.787, sensor resolution of 0.284°, and figure of merit of 78.766 RIU−1. Therefore, we believe that the introduced design of our ASPR sensor presents a good candidate for an accurate and efficient detection of low concentrations of contaminated water and sodium chloride as well.

Visible and angular interrogation of Kretschmann-based SPR using hybrid Au–ZnO optical sensor for hyperuricemia detection

Uric acid is a waste product of the human body where high levels of it or hyperuricemia can lead to gout, kidney disease and other health issues. In this paper, Finite Difference Time Doman (FDTD) simulation method was used to develop a plasmonic optical sensor to detect uric acid with molarity ranging from 0 to 3.0 mM. A hybrid layer of gold-zinc oxide (Au–ZnO) was used in this Kretschmann-based Surface Plasmon Resonance (K-SPR) technique with angular interrogation at 670 nm and 785 nm visible optical wavelengths. The purpose of this study is to observe the ability of the hybrid material as a sensing performance enhancer for differentiating between healthy and unhealthy uric acid levels based on the refractive index values from previous study. Upon exposure to 670 nm wavelength, the average sensitivity of this sensor was found to be 0.028°/mM with a linearity of 98.67 % and Q-factor value of 0.0053 mM−1. While at 785 nm, the average sensitivity is equal to 0.0193°/mM with slightly lower linearity at 94.46 % and Q-factor value of 0.0076 mM−1. The results have proven the ability of hybrid material Au–ZnO as a sensing performance enhancer for detecting uric acid when compared with bare Au and can be further explored in experimental work.

Theoretical Modeling of Surface Plasmon Resonance Biosensor Using Titanium Dioxide and Graphene Nanomaterial for Refractive Index Sensing

The most popular method to determine the sensitivity of surface plasmon resonance (SPR) sensors in the last couple of decades has been angular interrogation. The silver layer (Ag), a 2D layer of TiO2, and dielectric material layer such as silicon (Si) with heterostructure material graphene are all stacked in the proposed SPR sensor. To increase sensitivity of SPR sensor in the visible area, the device structure focuses on the Kretschmann configuration, by which a TiO2 sheet is sandwiched between silver and silicon sheets. The proposed device structure makes use of the operational wavelength of 633 nm. The numerical simulation has been performed in MATLAB software in this device structure. The simulation results show that an analyte of refractive indices ranges 1.345–1.350. A single layer of silicon 3 nm and TiO2 10 nm makes up the suggested SPR configuration, which increases the sensitivity to 281° RIU−1. Herein, it has also been computed the figure of merit, detection accuracy, limit of detection, full width at half maximum, and transverse magnetic electric field intensity. The biomedical and chemical fields have benefited from the proposed SPR sensor structure design.

Multilayer designs comprising zirconium nitride and perovskites as a novel angular plasmonic biomedical sensor

Abstract In this paper, a comparison between different configurations of surface plasmon resonance (SPR) biosensors has been theoretically conducted to improve the performance of the designed biosensor. The proposed biosensor configurations contain zirconium nitride (ZrN) as an alternative plasmonic material, which comprises different perovskite materials (KNbO3, LiTaO3, LiNbO3, SrTiO3, and BaTiO3) in the visible region. Depending on the study calculations, the reflection spectra of the suggested designs were studied under the angular interrogation mode based on Fresnel coefficients for the transverse magnetic polarized light. The numerical findings demonstrated that the SPR biosensor, which has the configuration of [Prism/BaTiO3/ZrN/BaTiO3/Biosensing medium], represents the best biosensor due to its higher sensitivity and minimum reflectivity values. Meanwhile, sensitivity could receive 179.58 (deg/RIU). Therefore, it is believed that the proposed SPR biosensor designs could be promising through wide-ranging applications, specifically in biomedical, chemical, and environmental protection.

Enhanced refractive index sensing using a surface plasmon resonance sensor with heterostructure

This article aims to enhance the sensitivity of a surface plasmon resonance sensor for refractive index sensing in the visible region using a low refractive index prism. The proposed sensing system is ultrasensitive and employs an angular interrogation method for measuring reflected intensity. The bimetallic layers and two-dimensional heterostructure are utilized to increase sensitivity. Black phosphorus is utilized as an analyte-interacting layer due to its sp3 hybridized puckered structure, high charge carrier density, indirect bandgap and larger surface area for attachment of analyte. To optimize the sensor structure and architecture based on its sensitivity and figure of merit, a comprehensive analysis is performed. The proposed sensor achieves the best possible sensitivity of 345.83°/RIU, detection accuracy of 0.132 Deg−1 and figure of merit of 45.74/RIU. This work enables to design a highly sensitive refractive index sensor useful to sense small sized analyte. The proposed research work provides new dimension to develop highly sensitive refractive index sensor for biomolecule or biochemical sensing.

Numerical Investigation on High-Performance Cu-Based Surface Plasmon Resonance Sensor for Biosensing Application.

This numerical research presents a simple hybrid structure comprised of TiO2-Cu-BaTiO3 for a modified Kretschmann configuration that exhibits high sensitivity and high resolution for biosensing applications through an angular interrogation method. Recently, copper (Cu) emerged as an exceptional choice as a plasmonic metal for developing surface plasmon sensors (SPR) with high resolution as it yields finer, thinner SPR curves than Ag and Au. As copper is prone to oxidation, especially in ambient conditions, the proposed structure involves the utilization of barium titanate (BaTiO3) film as a protection layer that not only preserves Cu film from oxidizing but enhances the performance of the sensor to a great extent. Numerical results also show that the utilization of a thin adhesive layer of titanium dioxide (TiO2) between the prism base and Cu film not only induces strong interaction between them but also enhances the performance of the sensor. Such a configuration, upon suitable optimization of the thickness of each layer, is found to enhance sensitivity as high as 552°/RIU with a figure of merit (FOM) of 136.97 RIU-1. This suggested biosensor design with enhanced sensitivity is expected to enable long-term detection with greater accuracy and sensitivity even when using Cu as a plasmonic metal.

Manipulation of sensitivity of the surface plasmon polariton waves at the interface of high magneto-optical medium and silver metal using angular interrogation

In this manuscript, sensitivity of the surface plasmon polariton waves (SPPs) using angular interrogation is coherently manipulated at the interface of four level high magneto-optical medium and silver metal using prism geometry. The control and probe fields detuning, Rabi frequency and decay rate manipulated significantly the angular interrogation of sensitivity of the surface plasmon polariton waves. The permittivity ϵd and permeability μd of the high magneto-optical medium play an important role in the manipulation of the sensitivity. The sensitivity is a function of control field detuning. The maximum sensitivity is reported to 800 deg/RIU with control field detuning. The minimum sensitivity is investigated to 6 deg/RIU with probe field detuning and Rabi frequency of control field. The reported results have useful applications in data storage and chemical sensing technologies.

Numerical and analytical analysis of an ultrahigh sensitive surface plasmon resonance sensor based on a black phosphorene/graphene heterostructure.

In this study, a surface plasmon resonance biosensor using angular interrogation based on a black phosphorene (BP) and graphene (G) heterostructure as two-dimensional materials are designed to enhance the sensitivity of conventional biosensors. The proposed structure is composed of eight layers: FK51A coupling prism, silver (Ag) thin film as the plasmonic metal, gold (Au) nanolayer in a protective role, BP nanosheets as an evanescent field enhancer, G monolayer as an immobilization process facilitator, DNA aptamer as biorecognition element, and phosphate buffered saline as a running buffer and sensing medium. To evaluate the performance of the proposed biosensor, analytical parameters such as minimum reflectivity (R m i n ), sensitivity, as well as the full width at half-maximum (FWHM), detection accuracy (DA), and quality factor (QF) are systematically assessed by the use of the transfer matrix method analytically and the finite-difference time-domain method numerically, to validate each other. It is observed that the structure has been optimized with 1.49 (RIU) for the coupling prism and the heterostructure T i O 2/A g/A u/B P/G thicknesses of 65/35/1/3.18/0.34nm, respectively. It was revealed that the proposed biosensor offered the sensitivity of 356 (°/RIU), QF of 42.4 (R I U -1), R m i n of 0.07 (a.u), FWHM of 8.3 (degree), and DA of 0.22 (unitless) and outperformed those of other results published up to now from the sensitivity point of view.

Development of a biosensor based on a surface plasmon resonance structure comprising strontium titanate, graphene and affinity layers for malaria diagnosis

This paper investigates the numerical analysis of a highly performed surface plasmon resonance (SPRE)-based sensor employing a hybrid structure of SrTiO3 (STO) and graphene for rapid detection of malaria. The investigation is performed using the angular interrogation technique and transfer matrix method. The SPRE device has a glass prism, silver (Ag), STO, graphene, affinity layer and sensing medium (SGM). Four coupling prisms are examined and we found the prism N-FK51A corresponds to the highest sensitivity. The sensitivity of the structure N-FK51A/Ag/STO/graphene/affinity layer/SGM is found to be 205.405, 222.222 and [Formula: see text]/RIU for Schizont, Trophozoite and Ring malaria stages. The layer thicknesses are then optimized and it is found that the proposed SPRE sensor can achieve a sensitivity of 278.378, 227.027 and [Formula: see text]/RIU for Schizont, Trophozoite and Ring malaria stages with 30 nm (silver), 1[Formula: see text]nm (STO), mono-sheet of graphene and 5[Formula: see text]nm of the affinity layer. These findings demonstrate that the proposed method and structure can be used efficiently for biomedical applications.

A novel tunable metal-clad planar waveguide with 0.62PMN-0.38PT material for detection of cancer cells.

A dynamically tunable metal clad planar waveguide having 0.62PMN-0.38PT material is simulated and optimized for detection of cancer cells. Angular interrogation of the TE0 mode of waveguide shows that critical angle increases greater than the resonance angle with increasing of cover refractive index, which limits the detection range of waveguide. To overcome this limitation, proposed waveguide applies a potential on the PMN-PT adlayer. Although a sensitivity of 105.42 degree/RIU was achieved at 70 Volts in testing the proposed waveguide, it was found that the optimal performance parameters were obtained at 60 Volts. At this voltage, the waveguide demonstrated detection range 1.3330-1.5030, a detection accuracy 2393.33, and a figure of merit 2243.59 RIU-1 , which enabled the detection of the entire range of the targeted cancer cells. Therefore, it is recommended to apply a potential of 60 Volts to achieve the best performance from the proposed waveguide.

Enhanced detection accuracy and signal-to-noise ratio of surface plasmon resonance based refractive index sensor with the addition of thicker layer of Silicon

The improvement in the sensitivity performance of conventional surface plasmon resonance (SPR) based sensors with the addition of thin layers of various high index dielectrics (e.g. 5 nm–10 nm of Silicon) is well established. This improvement in sensitivity comes at a price of reduced detection accuracy, deteriorated signal-to-noise ratio (SNR) and small value of Figure of Merit (FOM). Sensors with high detection accuracy and SNR find applications in the direct detection of small molecular (few hundreds of Daltons) interactions or low molecular concentrations (physiological concentration) on the surface of the sensor. The current paper presents design methodology and theoretical analysis of the performance of SPR based refractive index sensor with enhanced SNR, detection accuracy, and FOM attained when a thicker layer of Silicon (60 nm–400 nm thickness) is introduced in the conventional Kretschmann configuration employing angular interrogation technique. The analysis is valid for any high index dielectric layer that is used to enhance the electromagnetic field associated with the surface plasmon (SP) mode excited at the metal-dielectric interface. In the present paper, we show that the SP mode which participates in the sensing applications can be excited at the metal-dielectric interface for multiple thicknesses of Silicon. Analytical expressions are derived to compute the multiple thicknesses of Silicon using a modal analysis as well as the transfer matrix method (TMM) by considering the SPR sensor as a multi-layered optical waveguide structure. The refractive index SPR sensor with thicker silicon layer is shown to exhibit a long propagation length and large penetration depth in the analyte region, resulting in a higher depth-to-width ratio (defined as the SNR) and detection accuracy in its SPR reflectivity spectrum, hence enhancing the measurement precision of the sensor.

A Highly Sensitive Sensing Technique via Surface Plasmons With Tunable Prism Refractive Index

A new perspective using Kretschmann configuration is presented to excite surface plasmon polaritons (SPP) at liquid crystal (LC)/metal interface. The excitation of SPP takes place through the electrical tuning of the prism refractive index instead of the commonly used angular interrogation. The results show that the proposed methodology is 30% superior to the traditional angular interrogation. The 5CB (4-pentyl-4’-cyanobiphenyl) is one of the best suited nematic LC material for the proposed detection framework. Its refractive index is linearly tunable in the range 1.55 ~ 1.78 (at wavelength 1.55 μm) via an external applied electric field. In that range of refractive index variation, the SPP modes are efficiently excited; and hence any minute variation in the analyte refractive index can be detected reliably and accurately through a simple tuning of the refractive index of the prism LC material. The fundamental characteristics of the sensor are assessed through the evaluation of the linearity, sensitivity (S), the full width at half maximum (FWHM) of the reflectivity curve and the figure of merit (FOM). The variation of these characteristics over a whole range of analyte refractive index (1.3–1.4) are presented as well. The electrical tuning provides a well-matched design with micro-scale devices.

Design and modeling of an angular interrogation based surface plasmon resonance biosensor for dengue virus detection

Design and modeling of an angular interrogation based surface plasmon resonance biosensor for dengue virus detection

Designing high sensitivity and high figure of merit SPR biosensor using copper and 2D material on CaF2 prism

This theoretical work proposed an ultra-high sensitive hybrid structure for modified Kretschmann configuration comprised of copper-2D material layer on CaF2 prism for biosensing applications through angular interrogation method. Here, it is reported that such a configuration in association with the low refractive index CaF2 prism provides major contribution for improving the sensitivity. Using 2D materials in the proposed configuration not only acts as a medium for trapping biomolecules but also protect copper from becoming oxidized. On the basis of transfer matrix method, the thickness of copper layer suitability and the number of 2D layers are optimized to achieve high sensitivity, small FWHM, and minimum reflectance. Numerical results shows that a well optimized structure can achieves outstanding results exhibiting sensitivity as high as 514°/RIU with high FOM as 208.09RIU−1. Hence, copper and well optimized 2D material coated on CaF2 prism can be an excellent approach in sensor design for detecting biomolecules.